1. Field of the Invention
The invention relates to the control of call features within a stored program controlled telecommunication switching system and, more particularly, to a system for managing the interaction of a plurality of such features within a network.
2. History of the Related Art
Stored program controlled telecommunication switching systems and networks provide not only conventional two party interconnection services, but many additional calling features as well. In recent years subscribers have demanded, and telecommunications system operators have provided, many new "features" which incorporate functionality beyond conventional two party A to B calls, for example, features such as call waiting, multi-party conference, voice messaging, call forwarding and many others. Features are generally invoked and controlled by means of a controlling subscriber signalling the system with switch hook flashes, or the dialing of certain digits, each referred to as an "event". However, there are a limited number of events which can be caused by a subscriber and a large number of potential features which can be invoked and/or controlled by the same events.
As the number of available features offered within a telecommunication switching network increases, the possible interaction between the features becomes highly significant and a source of both potential confusion to the subscriber as well as faults within the network. For this reason, feature managers are provided within the switching system which manage the functionality of each feature in such a way that the different aspects of the functionality is coordinated. A feature manager monitors each event which occurs and directs that event to the feature logic of the software block implementing a feature which requires that event for invocation and/or control. However, when more than one feature requires the same event, the situation becomes more complex and requires that access to certain features be suspended and/or prioritized when other features are in use by a subscriber. Thus, marketing and administration of a large array of features to subscribers requires the provision of a "feature interaction listing" indicating the particular feature priorities and prohibitions which are applicable within the system depending upon which particular features are either currently in use or currently being invoked by a subscriber. This is not a good solution in that a subscriber who has paid for a particular feature within his subscription, should not be inhibited from using that feature simply because he is currently using a related feature with which there is an event conflict or because the software is unable to implement both features at the same time.
Moreover, as telecommunication solutions become increasingly network oriented, there is a great need for the provision of a feature interaction manager to monitor the occurrence of events within both the switch and network and coordinate the activities of the various feature managers to ensure that the correct features receive the event in the correct order so that implementation of the features does not disrupt the behavior of the switch or network in an adverse way. The system of the present invention provides such a feature interaction manager.